Extraction of Caffeine from Tea Leaves Santos, Raphael, Samson, Nonia Carla, *Tabora, Brylle, Tan, Kate Michal Department of Biological Sciences, University of Santo Tomas, Manila, Philippines Abstract Tea leaves are natural products that are harvested from agriculture. Caffeine, on the other hand, is a stimulant that has been shown to speed up the time of reaction, increase alertness, and improve one’s concentration. What we did in this experiment was to extract the alkaloid caffeine content from the tealeaves.
We had isolate and purify the leaves in the teabag so that we could acquire what is called a “pure caffeine. ” Introduction Beverages such as tea and coffee consist of high amounts of caffeine. Caffeine is a stimulant that enhances one’s concentration and alert level. Caffeine is classified as an alkaloid, which is used for substances produced as end products of nitrogen metabolism in some plants. It is also among a large group of nitrogenous substances found in natural plants.
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Although the plant may be poisonous and may be bitter-tasting, many of its extracts are pharmacologically active and may cause a person to have changes in his psychology. Some examples of alkaloid are atropine, coniine, morphine, nicotine, quinine, and strychnine. In the experiment, we had to isolate, which is to separate a substance in pure form from a mixture; purify, which is to rid the tealeaves of impurities; and characterize, which is to describe the quality of the caffeine in the tealeaves. Results and Discussion Figure 1. 1 Solid-liquid extraction
Figure 1. 2 Liquid-liquid extraction You would see in this figure a CH2Cl2 layer and water layer has formed. The CH2Cl2 that is in the lower layer was drained into a clean flask. This was repeated twice until all the CH2Cl2 was combined. Thereafter, it was put into a separatory funnel where it was washed with 20 ml 6M NaOH solution. The latter was discarded after. | Figure 2. Purification The crude caffeine was transferred in a filter tube with a fitted inner test tube and into a hot air bath for 35 minutes. It was constantly refilled with ice water.
Figure 3 Characterization of crystalline caffeine The crystals are packed at the bottom of the tube. It was allowed to fall inside a 1-meter long glass tubing and was also allowed to bounce up and down the tabletop. Table 3. 1 Tea leaves and caffeine results Weight of Tea Leaves | 2. 5g| Crude caffeine (color/description)| White/powdery| Pure Caffeine| | Weight | 0. 0180g| Color| White/clear| Physical state| crystal| %yield| 0. 22%| Calculations: % yield 0. 0180g8. 3107g=0. 22% In order to get the percent yield, the weight of caffeine over weight tea leaves multiplied by 100.
The weight of the pure caffeine is the weight of the watch glass with caffeine crystals minus weigh of of watch glass. Analytical balance was used to measure the weight of the substances. Weight of caffeineWeight of tea leaves x 100=Percent yield Experimental Our group opened three bags of tea and weighed its content on a pre-weighed evaporating dish using an analytical balance. All the weights were combined and recorded. After which the tea leaves were put back in the bags. It was then boiled in 100mL distilled water for about five manures.
After cooling the aqueous tea extract, it was transferred to a separatory funnel. The aforementioned was then mixed with 20mL CH2CL2 with pressure being released every so often. Thereafter, the organic layer at the lower part was collected. It was the process with the separatory funnel was repeated. References Donald L. Pavia, G. M. Introduction to Organic Laboratory Techniques : A Small-Scale Approach. Prueksaritanon, K. R. (10/18/2006). introduction to Organic Chemistry Technique. Wade, L. G. (12456). Organic Chemistry (5th ed. ). Prentice hall.